<?php

    /**
     * PHPExcel_Worksheet_RowIterator
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_Worksheet
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */
    class PHPExcel_Worksheet_RowIterator implements Iterator {
        /**
         * PHPExcel_Worksheet to iterate
         * @var PHPExcel_Worksheet
         */
        private $subject;
        /**
         * Current iterator position
         * @var int
         */
        private $position = 1;
        /**
         * Start position
         * @var int
         */
        private $startRow = 1;
        /**
         * End position
         * @var int
         */
        private $endRow = 1;

        /**
         * Create a new row iterator
         * @param    PHPExcel_Worksheet $subject  The worksheet to iterate over
         * @param    integer            $startRow The row number at which to start iterating
         * @param    integer            $endRow   Optionally, the row number at which to stop iterating
         */
        public function __construct(PHPExcel_Worksheet $subject, $startRow = 1, $endRow = null) {
            // Set subject
            $this->subject = $subject;
            $this->resetEnd($endRow);
            $this->resetStart($startRow);
        }

        /**
         * (Re)Set the end row
         * @param integer $endRow The row number at which to stop iterating
         * @return PHPExcel_Worksheet_RowIterator
         */
        public function resetEnd($endRow = null) {
            $this->endRow = ($endRow) ? $endRow : $this->subject->getHighestRow();
            return $this;
        }

        /**
         * (Re)Set the start row and the current row pointer
         * @param integer $startRow The row number at which to start iterating
         * @return PHPExcel_Worksheet_RowIterator
         * @throws PHPExcel_Exception
         */
        public function resetStart($startRow = 1) {
            if ($startRow > $this->subject->getHighestRow()) {
                throw new PHPExcel_Exception("Start row ({$startRow}) is beyond highest row ({$this->subject->getHighestRow()})");
            }
            $this->startRow = $startRow;
            if ($this->endRow < $this->startRow) {
                $this->endRow = $this->startRow;
            }
            $this->seek($startRow);
            return $this;
        }

        /**
         * Set the row pointer to the selected row
         * @param integer $row The row number to set the current pointer at
         * @return PHPExcel_Worksheet_RowIterator
         * @throws PHPExcel_Exception
         */
        public function seek($row = 1) {
            if (($row < $this->startRow) || ($row > $this->endRow)) {
                throw new PHPExcel_Exception("Row $row is out of range ({$this->startRow} - {$this->endRow})");
            }
            $this->position = $row;
            return $this;
        }

        /**
         * Destructor
         */
        public function __destruct() {
            unset($this->subject);
        }

        /**
         * Rewind the iterator to the starting row
         */
        public function rewind() {
            $this->position = $this->startRow;
        }

        /**
         * Return the current row in this worksheet
         * @return PHPExcel_Worksheet_Row
         */
        public function current() {
            return new PHPExcel_Worksheet_Row($this->subject, $this->position);
        }

        /**
         * Return the current iterator key
         * @return int
         */
        public function key() {
            return $this->position;
        }

        /**
         * Set the iterator to its next value
         */
        public function next() {
            ++$this->position;
        }

        /**
         * Set the iterator to its previous value
         */
        public function prev() {
            if ($this->position <= $this->startRow) {
                throw new PHPExcel_Exception("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
            }
            --$this->position;
        }

        /**
         * Indicate if more rows exist in the worksheet range of rows that we're iterating
         * @return boolean
         */
        public function valid() {
            return $this->position <= $this->endRow;
        }
    }
